Sony GY-2120WD Maintenance Manual page 240

6-2. Command Description
c) All Check (Self-diagnosis command No. 21)
Enter "21" as a command number and press the ENTER key.
Command numbers 22 and 23 are checked automatically and continuously.
DIAGNOSTIC=>21
-------[ RAM Check(SYS CPU) ]-------
RAM Check
-------[ ROM Check(SYS CPU) ]-------
ROM Check
SYS CPU Test
DIAGNOSTIC=>_
In case that the check succeeds;
Message "SYS CPU Test ******** OK ********" is displayed lastly.
In case that the check fails;
Refer to "In case that the check fails;" of the each corresponding command (number).
6-16
******** OK
******** OK
******** OK ********
GY-2120WD/WS